Banco do Brasil S.A. is a Brazilian financial services company headquartered in Brasília, Brazil. The oldest bank in Brazil, and among the oldest banks in continuous operation in the world, it was founded by John VI, King of Portugal, on Wednesday, 12 October 1808. It is the second largest banking institution in Brazil, as well as the second largest in Latin America,. Banco do Brasil is controlled by the Brazilian government and is listed at the B3 stock exchange in São Paulo.

Dom John VI, nicknamed "the Clement", was King of the United Kingdom of Portugal, Brazil and the Algarves from 1816 to 1825. Although the United Kingdom of Portugal ceased to exist de facto beginning in 1822, he remained its monarch de jure between 1822 and 1825. After the recognition of the independence of Brazil under the Treaty of Rio de Janeiro of 1825, he continued as King of Portugal until his death in 1826. Under the same treaty, he also became titular Emperor of Brazil for life, while his son, Emperor Pedro I, was both de facto and de jure the monarch of the newly independent country.